I'm curious - has the effect this 'sagging' on IQ been documented somewhere, and if so, can you provide a link? I've used the M + adapter + 85L II on a tripod, mounted via the adapter's foot, and I didn't notice anything manifestly obvious.

See the link I provided in the other post. The whole article is about lens adapters and their effect on IQ.

I'm curious - has the effect this 'sagging' on IQ been documented somewhere, and if so, can you provide a link? I've used the M + adapter + 85L II on a tripod, mounted via the adapter's foot, and I didn't notice anything manifestly obvious.

See the link I provided in the other post. The whole article is about lens adapters and their effect on IQ.

Thanks for the link. I don't see the connection to lens weight and 'sagging', though.

Lens adapters can cause issues. The lens mount on a camera is tested and even shimmed to a extreme tolerance. Add a cheap Chinese made lens adapter, and its pot luck.

Up until the Earthquake, Nikon kept the manufacturing of lens mounts in house so they could control tolerances. They finally picked a outside contractor when their production was shut down due to lack of lens mounts. Those sub 1/10,000 tolerance parts are extremely difficult to make and to measure.

Well, it would be possible for mirrorless cameras to take off even with the current (EF-M) lens mount, but it would require being able to get a much, much wider range of EF-M lenses than the three (at last count) that are currently available. IMO, as long as most EF-M camera users have to use the adapter with full-size lenses (along with the corresponding IQ loss), I would expect the EF-M cameras to continue to be largely stillborn except as cheap backup bodies.

Of course, if Canon really wants EF-M cameras to be more popular, there's one easy way: offer lens crossgrades, in which they take an existing EF or EF-S lens and change the mount to a solidly built EF-M mount so that it doesn't require an adapter, and also sell the EF-M variants as an additional SKU. (Ideally, they should also provide a crossgrade service, at least for the non-EF-S lenses, to turn those EF-M variants back into EF lenses for when EF-M users decide to upgrade to full-frame cameras.)

Such a crossgrade service would require almost zero additional engineering (it would just require replacing a few body pieces) and would jump-start the EF-M platform to some degree, as current EF-S camera users would see a viable upgrade path for their existing gear. Such a scheme might eventually allow EF-M to cannibalize the EF-S camera body market.

This is where this idea goes see ya --- if the economy was booming and disposable money was plentiful then yeah, lets dump a ton into building a new thing!!! But, money isn't growing on that many trees.

The simplest way to have mirrorless take hold here is -- forget about designing crossgrade mounts...forget about adaptors - a native mount for EF lenses!!!

Why do I say this --- well because the general public does not want anything with interchangeable lenses--- whats the current consumer mantra - 1 device, connectivety with social networks. An in camera crop to make a blurry image is better in the eyes of most than having to carry more than 1 device...much less extra lenses.

See above, this is why i feel like mirrorless has to ditch this idea of being smaller than DSLR's - make them the same size and form factor, make them use the current stock of EF lenses, then you've got a user base that does care about IQ, a user base that is more likely to take their images home to post process rather than upload to facebook then forget the image is on the memory card.

If the lenses are the same for each system then all the R&D can go towards designing a better body - as opposed to redesigning optics - it's a win for manufacturers and and consumers.

But, if the trend of trying to make mirrorless fill this gap between the SLR and cell phones, and the emphasis is on small and light...then it's DOA --- unless Canon and nikon are changing gears and making cell phones....

Edit -- As to EF-s Lenses ---this is where the whole mirrorless concept needs to figure out it's identity! Isw it the glorified P&S's canon and nikon and most of the others have released? Or will it follow a similar model to what Sony just released with their FF bodies? Again, what is the identity of mirrorless -- is it a niche fad midlevel attempt to tempt those that favor their cell phones or is it going to be a serious system that pros and enthusiasts will not only see as viable, but want and or shall I go as far as saying - need?

Mirrorless world domination is for certain. Resistance is futile. Connected, Excellent Mirrorless cameras very soon will offer better functionality than any mirror-slapper at significantly lower cost (= at somewhat lower prices for buyers and considerably higher margins for makers).

The conversion is just taking a bit longer, because makers wanted to dump their old tech stuff without connectivity (wifi, 4g) onto the markets first and have refused - until the very receent sony a7/r - to offer really worthehile mirrorless camera systems for enthusiasts use. Since virtually every picture taker who values iq has one or more perfectly functional dslrs already, it takes much more to win them over than half-assed consumer crap like an eos-m, a sony nex or a samsung nx with painfully limited photographic and ergonomic functionality.

market saturation + economic crisis + very conservative customer base = difficult environment for "entry level" new technology. This will change rapidly as soon asmore highly specced MILC cameras and systems will be available at very attractive pricepoints.

999 usd/€ for a fully capable ff body (say with 70d level of performance and nikon d7100 sensor quality and full connectivity wifi+4g+social networks + professional networks) will come. And usd/€ 1999 hi res ff milc will not only be available from sony (a7r) but with 5d IV functionality (af, 30+mp sensor, performance and 8 fps) from canon. The more people hild off buying either mirror-slappers or low-spec half-assed milcs like eos-m, the sooner we will get really good milc systems. Of course with a full range of smaller and better native, short-flange lenses. And of course with fully functional easy adapters for our existing glass if we dont mind its size or if some lenses (super-teles) cannot be made significantly smaller for the time being until new technology like DO or whatever also take care of that. :-)

The simplest way to have mirrorless take hold here is -- forget about designing crossgrade mounts...forget about adaptors - a native mount for EF lenses!!!

But why would someone choose that over a DSLR? The only real advantage I see to mirrorless is the short flange distance, which makes it possible to build wider non-retrofocus wide-angle lenses. I mean, I guess you could achieve that to some degree by making lenses that stick way out beyond the flange a la the EF-S 10–22, but some lenses, like the 22mm pancake, would probably be impossible with a larger flange distance (or, more precisely, would not be pancake lenses anymore).

The simplest way to have mirrorless take hold here is -- forget about designing crossgrade mounts...forget about adaptors - a native mount for EF lenses!!!

But why would someone choose that over a DSLR? The only real advantage I see to mirrorless is the short flange distance, which makes it possible to build wider non-retrofocus wide-angle lenses. I mean, I guess you could achieve that to some degree by making lenses that stick way out beyond the flange a la the EF-S 10–22, but some lenses, like the 22mm pancake, would probably be impossible with a larger flange distance (or, more precisely, would not be pancake lenses anymore).

therein lies the problem - the selling points for mirrorless really just aren't there, yet. To use the only analogy I can really think of...home entertainment - releasing a component to an existing system, yeah, no biggie...if its better you buy it. But - we're not talking one component, we're talking about an entire system. bodies and lenses - that's a big shift not only for the consumer but the manufacturers too.

To put it another way ---what has a better chance of success - release of a new FF mirrorless body that uses currently made lenses by design? One that anyone currently using the system can purchase with no additional needs? Or, a system that has less options of glass and needs to have special glass?

Seriously, raise your hands here --- if Canon were to release a Mirrorless FF body, same form factor as the 5 series, that used Ef lenses, regardless of spec's, raise your hands if you'd be thinking about owning one? Spec it out 6dish and price it at $1900, who's raising your hands? Hell, that could be a fun backup camera.

Or:

FF Mirrorless, small, lighter, but only a handful of lenses to choose from? (or an adaptor to use Ef lenses which to me just seems real real awkward, and would also cost you some IQ or Aperture or AF capabilities/accuracy?)

I'm hoping Canon just makes a third mount type that takes both EF lenses and allows lenses that sink 10-20mm into the body. You could have a 20mm pancake that only sticks out of the body far enough to have a switch and a focus ring.

The simplest way to have mirrorless take hold here is -- forget about designing crossgrade mounts...forget about adaptors - a native mount for EF lenses!!!

But why would someone choose that over a DSLR? The only real advantage I see to mirrorless is the short flange distance, which makes it possible to build wider non-retrofocus wide-angle lenses. I mean, I guess you could achieve that to some degree by making lenses that stick way out beyond the flange a la the EF-S 10–22, but some lenses, like the 22mm pancake, would probably be impossible with a larger flange distance (or, more precisely, would not be pancake lenses anymore).

The big advantage for mirrorless is the removal of the mirror. It degrades IQ by banging up and down and vibrating the whole Camera, it increases the cost. Its a rube Goldberg contraption.Find a way to make the mirror go away without losing performance, and you can eliminate vibration, sensor cleaning, and greatly improve reliability. I suspect that there are other improvements that are subtle, but every little bit adds up.A smaller camera is a benefit only for a few, it tends to be unbalanced with a big lens, and lenses do not get smaller just because a body is mirrorless.Canon has tried twice, and failed both times to sell SLR's with Pellicle mirrors (No moving parts), so they are going to be reluctant to stick their neck out until its a sure thing.

Find a way to make the mirror go away without losing performance, and you can eliminate vibration, sensor cleaning, and greatly improve reliability. I suspect that there are other improvements that are subtle, but every little bit adds up.

This is true, but also "just" a deficiency view - the potential of mirrorless is the combination with potential innovations, not just fixing old-school film slr design problems.

Today's dslrs are really awkward if you think about it, you've got an expensive, high-res sensor that is blind 99% of the time while you need to add a secondary complex af module just for this very reason, Canon has got it right in theory with the dual pixel af approach. Coupled with a fast cpu you can get a really "smart" af at the fraction of the cost for the 1dx face detection attempt... plus rgb metering for the rest of us :-)

Canon has tried twice, and failed both times to sell SLR's with Pellicle mirrors (No moving parts), so they are going to be reluctant to stick their neck out until its a sure thing.

There surely were problems with these designs, but at least on a personal level I wouldn't call it failure - I absolute adored my eos RT, you could actually *see* what you're shooting as there's no blackout and the shutter lag was incredibly low.

Well, it would be possible for mirrorless cameras to take off even with the current (EF-M) lens mount, but it would require being able to get a much, much wider range of EF-M lenses than the three (at last count) that are currently available. IMO, as long as most EF-M camera users have to use the adapter with full-size lenses (along with the corresponding IQ loss), I would expect the EF-M cameras to continue to be largely stillborn except as cheap backup bodies.

Of course, if Canon really wants EF-M cameras to be more popular, there's one easy way: offer lens crossgrades, in which they take an existing EF or EF-S lens and change the mount to a solidly built EF-M mount so that it doesn't require an adapter, and also sell the EF-M variants as an additional SKU. (Ideally, they should also provide a crossgrade service, at least for the non-EF-S lenses, to turn those EF-M variants back into EF lenses for when EF-M users decide to upgrade to full-frame cameras.)

Such a crossgrade service would require almost zero additional engineering (it would just require replacing a few body pieces) and would jump-start the EF-M platform to some degree, as current EF-S camera users would see a viable upgrade path for their existing gear. Such a scheme might eventually allow EF-M to cannibalize the EF-S camera body market.

This is where this idea goes see ya --- if the economy was booming and disposable money was plentiful then yeah, lets dump a ton into building a new thing!!! But, money isn't growing on that many trees.

The simplest way to have mirrorless take hold here is -- forget about designing crossgrade mounts...forget about adaptors - a native mount for EF lenses!!!

Why do I say this --- well because the general public does not want anything with interchangeable lenses--- whats the current consumer mantra - 1 device, connectivety with social networks. An in camera crop to make a blurry image is better in the eyes of most than having to carry more than 1 device...much less extra lenses.

See above, this is why i feel like mirrorless has to ditch this idea of being smaller than DSLR's - make them the same size and form factor, make them use the current stock of EF lenses, then you've got a user base that does care about IQ, a user base that is more likely to take their images home to post process rather than upload to facebook then forget the image is on the memory card.

If the lenses are the same for each system then all the R&D can go towards designing a better body - as opposed to redesigning optics - it's a win for manufacturers and and consumers.

But, if the trend of trying to make mirrorless fill this gap between the SLR and cell phones, and the emphasis is on small and light...then it's DOA --- unless Canon and nikon are changing gears and making cell phones....

Edit -- As to EF-s Lenses ---this is where the whole mirrorless concept needs to figure out it's identity! Isw it the glorified P&S's canon and nikon and most of the others have released? Or will it follow a similar model to what Sony just released with their FF bodies? Again, what is the identity of mirrorless -- is it a niche fad midlevel attempt to tempt those that favor their cell phones or is it going to be a serious system that pros and enthusiasts will not only see as viable, but want and or shall I go as far as saying - need?

Yes, I agree that not everyone wants a little camera mirrorless, it seems toy. I like DSLR but could buy a mirrorless that have full compatibility with EF and EF-S lenses. Why mirrorless has to fit in your pocket? Not in my pocket.

Is it the glorified P&S's canon and nikon and most of the others have released? Or will it follow a similar model to what Sony just released with their FF bodies? Again, what is the identity of mirrorless -- is it a niche fad mid-level attempt to tempt those that favor their cell phones or is it going to be a serious system that pros and enthusiasts will not only see as viable, but want and or shall I go as far as saying - need?

Some people won't like the answer, but here it is:

Professional-level mirror-less cameras have been around since at least the 1930s. For decades, only one manufacturer – Leica – has kept mirror-less alive and then only as a niche market product. Really, nothing of substance has changed. The cameras use electronic sensors instead of film, but all the other relative advantages or disadvantages of the rangefinder versus SLR form factors remain the same.

While a vastly improved electronic viewfinder might make mirror-less more competitive, it would still have huge hurdles to overcome. The mirror-less form factor is great as a light weight street camera, but it offers no advantage for many other applications, such as studio and portrait work. It may even be a disadvantage when using telephotos beyond about 135mm (Notice Leica doesn't even produce any longish telephotos).

So, given that, why should Nikon and Canon rush to produce a professional-level mirror-less camera? Far wiser to let Sony risk their resources on testing the market. If the technology improves and if Sony's sales figures show a true demand, Nikon and Canon can easily enter and very quickly dominate the market. There simply is no good business reason for them to risk their resources on an untested market. Better to let someone else take the risk.

But, I seriously doubt that Nikon and Canon are watching Sony nearly as closely as they are watching Fuji. Looking at the Fuji Pro series, it would be easy to make a case that the future of mirror-less is in the APS-C format, rather than full frame. It offers high image quality while retaining more of the size advantages that mirror-less can offer.

Over at Photorumors, they just published some sales numbers for Japan. For those who dream of a full-frame anything, they are quite eye-opening. Full frame mirror-less constitutes just .5% (that's 1/2 of 1 percent) of the total sales in Japan and in DSLRs, full-frame is just 8.7% of the sales. In short, it is "a small, small world after all" despite the skewed perspective one gets on this and other forums.

Mirror-less may someday displace DSLRs, but only when the technology proves superior, which is far from the case today. If it does eventually happen, it is likely to be a gradual, almost seamless transition, not some jarring "game changing" occurrence.

Seriously, raise your hands here --- if Canon were to release a Mirrorless FF body, same form factor as the 5 series, that used Ef lenses, regardless of spec's, raise your hands if you'd be thinking about owning one? Spec it out 6dish and price it at $1900, who's raising your hands? Hell, that could be a fun backup camera.

Or:

FF Mirrorless, small, lighter, but only a handful of lenses to choose from? (or an adaptor to use Ef lenses which to me just seems real real awkward, and would also cost you some IQ or Aperture or AF capabilities/accuracy?)

I would buy one without any hesitation if were realized as well as, say, the Olympus OM-Ds. The advantages of mirrorless strike me as significant. Not only is there no mirror flapping around causing vibrations, there's none of the focus inaccuracy induced by the complicated system required in a dslr - the need to adjust lenses to a camera body should be obsolete because you're focusing from the sensor: if the image looks in focus via the EVF then it is in focus (unless it's a crappy AF system such as used by Fuji, which often seems to think you should have focused on something else instead). EVF's have the advantage of letting you see the effect of adjustments on exposure etc. as you make them while looking through the viewfinder and make manual focus easy again (especially nice if you like to fool around with "legacy" lenses; the simple adapters involved there work just fine). What's more - and this is a huge advantage when avoiding focus-recomposing - the focus points can be almost edge-to-edge. These are the main reasons why I like mirrorless, and they have nothing to do with size/weight. I would love to be able to use my Canon lenses properly on such a camera, especially if, like Olympus, they were to throw in comparably good IBIS.

I like having an OM-D for when I don't want to lug heavy stuff around too. But the main reason M43 systems are small/light isn't because the bodies are; it's because the lenses can be, thanks to the smaller sensor. Unless you use it solely as a back-up and/or are one of the (presumably tiny) class of people who expect to use them on tripods, I see little point in a small camera body if the lenses are big, even if it's technically possible to attach them with flawlessly unobtrusive adapters; the results are ergonomically absurd (as far as I'm concerned, at any rate). That, and the lack of IBIS, are the main reasons why I've not bought one of the Sony A7s.

I had hoped that the next generation of Sony Alphas would be mirrorless, but it seems they'll keep using the same technology they've put in their modified dslrs, with their inferior low light performance (at least if the Sony rumor sites are to be believed). And if Sony won't do it, it's hard to imagine Canon stepping up.

pharp

I picked up an OM-D w/ 75-300 (supplement to Canon gear) - wonderful little, weatherproof kit for nature work. I am pleased with the EVF, especially for MF. The MF assist is wonderful and being able to switch from AF-MF using Fn button is excellent. It's not 'pocketable', but it is relatively small. MILC will take hold when mfr make enthusiast/pro cameras. Olympus evidently figured that out. The P&S crowd don't care about IL. I don't even have to think about taking the OM out, compared to a roughly equiv. 7D w/100-400. I'd buy a Canon high grade APS-C version (M w/EVF) if they made one, but ...

While a vastly improved electronic viewfinder might make mirror-less more competitive, it would still have huge hurdles to overcome. The mirror-less form factor is great as a light weight street camera, but it offers no advantage for many other applications, such as studio and portrait work. It may even be a disadvantage when using telephotos beyond about 135mm (Notice Leica doesn't even produce any longish telephotos).

I think that full-frame will continue to dominate studio & portrait. However, mirrorless offers some nice advantages for photographers who are on their feet covering events all day. The Leica limitation of 135mm relates to the rangefinder mechanism and won't be a disadvantage for new mirrorless cameras like the OM-D. Panasonic offers a 35-100/2.8 (70-200 equiv.) and Olympus will soon offer a 40-150/2.8 (80-300 equiv.). These telephoto zooms are much more compact & lightweight than their full-frame alternatives, while still offering nice depth of field control. The Panasonic 35-100/2.8 in particular weighs a small fraction of what a typical 70-200 weighs (13 ounces vs. 3 pounds). Likewise the Olympus 75/1.8 weighs a fraction of a what full-frame equivalent would weigh. I think the reduced size & weight will be a selling point for photographers who are tired of carrying around big telephoto zooms, especially now that the OM-D has improved autofocus.